During labor, physiological parameters such as fetal heart rate are monitored in order to identify signs of fetal distress, or warn that the fetus may not be well or is becoming excessively fatigued. Prior to labor, the mother may undergo one or more ultrasound exams, which provide fetal heart rate and fetal size information that is used to identify markers of fetal growth during pregnancy. Unfortunately, ultrasound exams can be expensive and typically are performed only once during pregnancy. Historically, mothers sense fetal movements and midwives have the mother count those movements. A moving fetus is felt to be a healthy fetus. With the increasing age of mothers, there has been an increase in difficult pregnancies which would benefit from exams.
The literature indicates a correlation between fetal health and fetal kicks with less healthy fetuses often having fewer kicks relative to healthy fetuses. In one instance, the mother senses fetal movements and fills in a kick chart when she believes a sensed movement is a fetal kick. A kick chart is a form or graph used by a pregnant woman in the later stages of pregnancy to record the activity of her fetus. Another approach is to have the mother carry or wear a manually activated counter. With this approach, the mother increments the counter rather than filling in the chart.
In either instance, fetal kick activity over time can be determined from the recorded information. As such, the recorded information can be used to identify changes and trends in the kicks that occur in a given time interval. Unfortunately, the above approaches require the mother to sense and record kick events. In addition, the recorded information may not accurately reflect the fetus' kicks as the mother may not sense all kicks during a kick observation time interval, the mother may not record all sensed kicks, a sensed movement thought to be a fetal kick may be a different type of movement such as rolling around, a sensed movement thought not to be a fetal kick may in fact be a fetal kick, and the fetus may be sleeping when the mother is actively attempting to sense fetal movement.